


Belonging

by Kirsten



Category: Criminal Minds
Genre: Canon-Typical Violence, Child Abduction, Collars, Harm to Children, Leashes, M/M, Murder, Porn Battle
Language: English
Status: Completed
Published: 2012-02-07
Updated: 2012-02-07
Packaged: 2017-10-30 18:57:05
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 4,262
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/334989
Author URL: https://archiveofourown.org/users/Kirsten/pseuds/Kirsten
Summary: <blockquote class="userstuff">
              <p>Aaron's birthday starts out bad, but Derek makes it better.</p>
            </blockquote>





	Belonging

**Author's Note:**

> Written for Porn Battle XIII using the prompt "collar", because [LaT](http://latxcvi.tumblr.com) wanted it.

The next case Aaron took was in DC. It was hard to resist. Three little boys murdered, all abducted in broad daylight from public places. He opened the case file and looked at their faces, their dark blond hair and happy smiles, and for a few seconds the only face he saw was Jack's.

"Conference room in ten," he told Garcia.

"Yes, sir, I will email copies to everybody," said Garcia, and left his office.

Aaron stayed behind his desk and skimmed the file. The boys were all under ten years of age. Jamie Carter disappeared from after school soccer practice, Adam Kaplinski and Boyd Hope from playgrounds and public parks. Adam was taken twelve days after Jamie, and Boyd seven days after that. In all cases, at least one parent was present.

Aaron's heart beat a little faster.

There was a knock at his office door. He'd been aware, in that distant way he always was, of the activity in the bullpen and the glances through his office window, but it was still a surprise to see Derek standing in the doorway.

"I saw the file," said Derek. He stepped a little further into the office, his hands comfortably in his pockets. "You okay?"

Aaron stared at him for a second, his mind's eye full of Jack playing soccer in the park a few miles away. He said, "The parents were there."

Derek nodded. Aaron looked back down at the photographs and saw Jack's face again. Derek's presence in his office said Aaron wasn't the only person who saw it. He took a deep breath and slowly exhaled, but it didn't help.

"Come on," said Derek. "We're ready."

-

Back before Derek joined the team, when Dave and Jason were running the show and Aaron was still new at the BAU, Aaron was usually partnered with a guy called Jim Deloitte. Jim liked to arrive at a crime scene a blank slate. Outside of the victim's name, age, and biological sex, he wanted nothing to interfere with his reading of the behavioural evidence. There was nothing fundamentally wrong with that approach, but it was anathema to Aaron. Preparation and argument, the constant testing and re-examination of theories - these were habits trained into him at law school, and they were hard to shake.

"We can't prepare for everything," he said to Derek, who rested a hand on his shoulder and squeezed.

They were out in the field while the rest of the team worked the case from the BAU. The Budget Oversight Committee would no doubt prefer they all worked it from the BAU, but the victimology had Aaron rattled. It was a post-traumatic reaction, he knew; the panicked need to keep Jack safe was familiar and sunk deep into his bones. It didn't happen often, but that didn't make it easier to bear.

Boyd Hope's body lay just beyond the battered double doors.

He really did look a lot like Jack.

"You know, nobody would blame you if you wanted to sit this one out," said Derek.

Aaron leaned against the wall and tipped his head back. He closed his eyes. The morgue lights glowed dim red through his skin. "I should be able to go in there." It was irrational, but the self-recrimination still tasted bitter in his mouth.

He opened his eyes when Derek's fingers brushed his cheek. It was a risky move, probably just as risky to be standing so close to each other, but the corridor was empty and quiet, and he trusted Derek's judgement.

"There is no 'should'," Derek said. His voice was firm, and his eyes were warm, and his hand was still hot on Aaron's shoulder. "I'm good at my job, and you're going to let me carry this. I'm going to finish up in there. You stay out here.” Derek squeezed his shoulder again. “Call Jack."

Aaron covered Derek's hand with his own. Derek smiled, and disappeared through the doors.

-

Jack, it turned out, was not playing soccer in the park, information which forced a quiet breath of relief from Aaron's lungs. Jack was safe at home with his Aunt Jessica, and they were making Aaron a birthday cake.

"It was supposed to be a secret," Jack said.

"Well, me knowing the secret can be our secret," said Aaron. "So it's still kind of a secret."

"That's stupid," said Jack, and Aaron chuckled.

It was chocolate cake. "It's all over the phone," Jack said, and he sounded puzzled about that. "It's sticky."

"Make sure you clean it up," said Aaron, who really didn't care about cake mix on the phone.

"Okay, Dad."

"You know, Mom and I made a birthday cake for Grandma Brooks once. It turned out flat because we kept opening the oven while it was baking. You have to keep the door shut."

"Everybody knows that, Dad," said Jack, his eyeroll at Dad's stupid loud and clear. "Aunt Jessica said."

"Okay, okay,” Aaron said, hand over his mouth to smother his laugh. “I love you.”

"I love you, too, Dad," said Jack.

They said goodbye, and Aaron hung up the phone feeling immeasurably better. The sense of desperation and inevitability had lifted. He stood there thinking about Jack and chocolate cake and childish secrets, and he beamed a little inside.

Derek came back out into the corridor and filled Aaron in on the evidence. “They were suffocated.”

“He smothered them?” 

“No,” said Derek. “There's plastic under their fingernails, and their fingertips are scratched raw. He locked them in an airtight box until they died because he didn't want to hear them scream.”

Derek's face was bleak, and it was Aaron's turn to risk a touch. Not for the first time, Aaron reflected that profiling was a skill both blessing and curse.

-

Forensic tests identified the plastic and revealed the presence of DNA on boys' bodies. The distribution pattern suggested the unsub was still learning what got him off. Derek caught the look on his face when Garcia emailed the lab report through to the station. Aaron caught the look on Derek's. 

"At least we're not dealing with a living victim," Aaron said, as if that were some comfort.

"Unless he's escalated again," Derek said.

Aaron watched Derek stare at the evidence board. His body was tense, so Aaron went over to him and stood close enough that their arms brushed. It was inappropriate, but Derek relaxed a little, and Aaron considered it another risk well taken.

He stared at the evidence board as well. 

The parents were linked through a city construction project, a plan to drive a major new road through existing homes. Most of the residents had taken the project's money and moved elsewhere, but some were still hanging on. Aaron could understand wanting to hold onto a home, a place where somebody could build memories around themselves. He could understand being angry when that place was taken away.

Detective Miller was running point on the investigation. She was grizzled but steady, and Aaron liked her a lot, right down to the old black boots on her feet and the cigarette smoke that clung to her hair. She came up behind them and coughed into her forearm. "Any brainwaves from the FBI?"

"Maybe," Aaron said. Reid had faxed over a construction plan and Aaron had pinned it to the evidence board. Aaron nodded at it. "How many people still live in the way of that road?"

-

Their unsub was a man named John Leonard. He was 43 and he lived across the street from an elementary school, where he was a janitor. He'd spent a lot of money on legal advice for a lot of different reasons, and he'd recently been declared bankrupt. His home was due to be auctioned in less than a month.

Aaron found a plastic box in the spare bedroom, just big enough for a child Jack's age. There were bloody scratches on the interior, and it stank of urine and feces.

Aaron shut his eyes for a second, then forced himself to look around the room. There was a bed, and nothing else. The window was boarded up. Aaron knew what had happened there. He knew how those boys had died, alone and terrified of the monster in the dark.

He walked out and bumped into Derek, who was about to walk in.

"You don't need to go in there," Aaron said.

"What?" Derek glanced over Aaron's shoulder then looked back at Aaron's face.

"Make sure Garcia gets his computer,” said Aaron. “I want to know everything this guy's done, and I want to make it stick."

Derek's arms twitched, an aborted movement. Aaron knew what it meant. The cold knot in his stomach eased a little. 

"Go get some air," Derek said, and the concern in his voice eased the knot a little more. 

-

People were looking sneaky when he and Derek arrived back at the BAU. They'd been gone for eight hours but Aaron felt like he'd been out of state for days, drained and exhausted, with some tiny part of himself crumpled in vague despair. He was desperate to see Jack, but people were looking sneaky, Garcia and Prentiss in particular, and that meant there was some sort of birthday surprise to get through first.

"The paperwork can wait until Monday," Aaron said to Derek as they stepped out of the elevator. He frowned. Derek was looking sneaky, too.

"Dad!" Jack's voice rang out across the bullpen, and Aaron watched with astonishment as his son ran down the steps from his office and came to a halt right in front of him. He stood there and grinned up at Aaron.

"Hi," Aaron said. He found himself grinning back, and then he was crouching down and tugging Jack into a careful hug. 

"Agent Derek told Aunt Jess the case made you sad," Jack said, his voice muffled by the shoulder of Aaron's suit jacket.

Aaron glared up at Derek. "Did he."

Derek shrugged, amused and unrepentant. Aaron stood up with Jack in his arms, and decided to let it go.

-

There was unsurprising chocolate cake in his office, along with presents from his team and a drawing from Jack. 

“But you already made me a cake,” Aaron said. He looked at the drawing. There was Agent Derek and Clooney to one side, and Dad and Jack and a puppy to the other, all helpfully labelled in Jack's seven-year-old script. Aaron pointed at the puppy and raised his eyebrow. Jack smiled hopefully, and Aaron sighed.

Garcia set a cup of tea in front of him. “Happy birthday, sir,” she said.

“Thanks,” Aaron said. “Help yourself to cake.”

The cake was good and so was the tea, and time passed surprisingly quickly. Aaron decided it was time to go home when Jack's head lolled against his shoulder. One by one his team filtered out, until there was only Derek left.

"I'm driving," Derek said, and held out his hand for the keys.

Aaron wouldn't have argued even if he'd had the energy for it. He hitched Jack more securely into his arms and stood.

"Do you want me to get that?" Derek pointed at his briefcase.

"No," Aaron said, and walked out the door.

-

It was close to nine by the time they got back to Derek's place. Clooney's noisy welcome woke Jack enough that Aaron could get him in the bathroom to wash up. Jack brushed his teeth slowly, his sleepy eyes blinking up at Aaron in the mirror. Aaron smiled, and smoothed a hand over Jack's hair.

Jack was too tired for reading. Instead he climbed straight into bed and hitched over to make room. Aaron sat next to him, and Jack curled up at his side.

"Dad," Jack whispered.

"What?" Aaron whispered back.

"Did you have a good birthday?"

Aaron leaned down and kissed the top of Jack's head. "The best," he said, and at that moment, it was the truth.

Jack drifted off to sleep, but Aaron couldn't bring himself to move. He lay there and listened to Jack's snuffling sleep breathing, and stroked Jack's hair. Jack's bedroom at Derek's place was peaceful, bigger and less cluttered than his room at their apartment. Aaron looked around in the darkness and shadows and thought about puppies. He smiled to himself and wondered if it was time to move house. 

Derek's camera clicked and flashed. Aaron winced and blinked. He heard Derek come closer, until he was close enough for Aaron to lean against his thigh. He closed his eyes when Derek started playing with his hair.

"Is he asleep?" Derek's voice was low.

Aaron nodded. His forehead brushed against Derek's sweatpants. "You changed."

"Had to get out of the uniform," Derek said, and Aaron chuckled. "Come on," Derek added. "He's out. Time to hit the hay. Besides -" Derek leaned down and murmured directly into Aaron's ear "- I have something for you."

Aaron shivered at the sensation of Derek's breath against his neck, but he took the time to carefully disentangle himself from Jack, who melted into the warmth left by Aaron's body. Aaron pulled the blanket up over his shoulders and rested a hand on his head for a second, then straightened up and turned around.

He smiled. Derek was wearing an old Northwestern t-shirt. It was a little tight on him because he wasn't twenty anymore, but Aaron wasn't about to complain. Derek grinned like he knew exactly what Aaron was thinking, and took Aaron's hand.

He closed the door to Jack's room and let Derek lead him down the hall to his bedroom. Derek tugged him inside and locked the door, then wrapped himself tight around Aaron's body.

"I wanted to do this all day," Derek said. His voice was relieved. Aaron kissed the side of his face and rested his hands on the small of Derek's back. He slipped his fingers under the waistband of Derek's sweats and rubbed his thumbs over Derek's skin. He could feel Derek smiling against his neck.

He liked Derek's room. It was neat but not too neat. It looked lived in. There was a lamp on the bedside and a pile of fitness magazines on the floor. Sometimes Derek read them before he fell asleep. It was a way to keep his thoughts away from the BAU and whatever he'd seen that day.

"Where's my present?" Aaron asked.

Derek laughed and let him go. There was a box on Derek's bedside, flat and square, and Aaron watched him pick it up. Derek paused and looked at Aaron in what Aaron could only call consideration.

"What?"

"Nothing," Derek said. "I'm just picturing something."

"Oh," Aaron said. His face warmed, and he knew he was blushing. It was _that_ kind of present.

Derek stood close beside him, close enough Aaron could feel the heat of his body, and handed Aaron the box. Aaron looked down at it and bit his lip. He could feel Derek's eyes on his face. He lifted the lid.

It was a collar.

It was black leather, thick and well made, with a D-ring at the front for a leash. Aaron swallowed and licked his lips. Arousal settled in his stomach. 

The overt sexuality of it wasn't the only thing that made his heart pound. It was everything else. They weren't experts at this, but there was symbolism to a collar. Ownership, and possessiveness, and belonging.

"I want you," Derek said, his voice low.

Aaron looked at him. He could see the truth of that in Derek's face. Derek wouldn't offer this lightly. It was a considered decision, something Derek had thought about for a long time. He'd thought about Aaron, the things Aaron liked when they were together, the things Aaron might need, and he'd thought about exactly the same things with reference to himself.

Aaron took the collar out of the box and then put it in Derek's hands. He unfastened his tie and dropped it to the ground, and then he started unbuttoning his shirt. Derek watched him undress with hungry eyes, and some part of Aaron began to preen under that attention.

When he was naked, Aaron asked, "How do you – where do you want me to -?"

Derek pushed him down so that they were both sitting on the bed. Derek put his hand to Aaron's face. "It's not about that," he said. "You know I don't want you kneeling in front of me unless you want it, too."

Aaron kissed him, passionate and lingering. Aaron felt Derek smile and he smiled back. He let Derek take hold of his shoulders and push him back a little.

"Here," Derek said. He lifted the collar, and Aaron lowered his head so Derek could fasten it at the back of his neck. The leather was cold against his skin, but it warmed quickly and sat heavily. Derek slid a couple of fingers underneath it and tested the give. "Okay?"

"Yes." Aaron lifted a hand and fingered the leather. He couldn't stop smiling, and he smiled even harder when Derek took hold of his fingers and directed his touch. "This is a pretty good birthday after all."

Derek's smile went soft and a little sad. He rested a hand on Aaron's face. “I'm sorry we caught that case.”

“It was hard for you too,” Aaron said, and kissed him again.

Derek pulled away. "Hold on." He reached back and slid his hand under the pillows. He pulled a leash into Aaron's view, a heavy silver chain with a clip at one end and a leather handle at the other, and held it up. "This is for me," he said, and held Aaron's gaze while he secured it to the collar.

Aaron heard the click and let out a heavy breath. Derek twisted the leather handle around his wrist and hand. He pulled on it firmly, and Aaron had no choice but to move closer. Then Derek got back to kissing him him, his free hand on Aaron's cheek. His thumb stroked Aaron's cheekbone. "Are you scared?" he asked between kisses.

Aaron gave the question all the consideration it deserved. "No," he said, tugging at Derek's shirt.

"Good." Derek took hold of his hands and pushed them back down. "Wait your turn," he said. His voice was stern, which made Aaron shiver, and his eyes were happy, which made Aaron smile.

Derek stood up, and then it was Aaron's turn to watch with hungry eyes. Derek's body still took his breath away. Knowing how hard Derek worked to maintain it only made Aaron appreciate it more. Derek was strong, but it was modulated strength, strength made gentle by Derek's thoughtfulness. His judgement was good; as soon as he was naked, he pulled Aaron forward with the leash and grasped the collar, holding Aaron's face to his groin.

Derek's cock was hard. It was so close to Aaron's mouth he could almost taste it. He inhaled deeply and strained forward to try and get his mouth on Derek's skin, but Derek held the collar tight and kept him still.

"I want to suck you," Aaron said. He nuzzled his head into the crease of Derek's hip and thigh and licked at whatever skin he could reach.

"Damn," Derek said, his voice a rough breath, but he didn't let go of the collar. Instead he pushed Aaron into place. Aaron let himself be pushed and licked at Derek's cockhead, tasted the pre-come, and then slid his mouth down the length of it. He glanced up at Derek and was gratified to see him watching with widened eyed.

Derek saw him looking and smiled. He thumbed Aaron's open lips. "You can use your hands," he said, so Aaron did exactly that. He wrapped the fingers of one hand tight around the shaft and cupped Derek's ass with the other, pushed his fingers into the crack of Derek's ass and brushed at his hole. Derek's hips jerked, and Aaron moaned when the leash briefly tugged at his collar.

Derek groaned and pushed Aaron away with a hand to his forehead. “Okay, enough.”

He was breathless, Aaron noted, not a little smug, ignoring his own breathlessness and the throbbing of his dick between his legs. He laughed. “Can't take it?”

“Oh, I'll show you take it,” Derek said, pulling Aaron to his feet. He held Aaron close, chest to chest. Derek's hand was back on Aaron's collar, his thumb stroking the skin below Aaron's ear. Aaron shivered again and rested his forehead against Derek's. 

“Gonna let me fuck you?” 

Derek's voice was low and hoarse. Aaron's brain interpreted the sound and the question as 'sexy'. He kissed Derek's neck, moved along his jaw to his mouth and licked his way inside. Derek's kisses were intoxicating. Aaron was dimly aware of Derek's hands and the way they skimmed down his back to cup his ass, the way Derek pulled him even closer and pushed a leg between his. He whimpered and rubbed his cock on Derek's thigh when Derek rubbed at his asshole and pushed the tip of one finger inside.

Derek dragged his lips away from Aaron's insistent kiss. “Well?”

“Yes. Yes,” Aaron said, emphasizing his consent.

Derek's smile was slow. Aaron's breath quickened as he watched Derek unwind the leash from around his hand. “I'm going to rock your world,” Derek promised

Aaron burst out laughing and then found himself tumbling back onto the bed with Derek all over him.

“Okay,” Aaron said. “That works for me. Rock my world,” he added, and tilted back his head so Derek could mouth at his collar and neck. He smoothed his hands down Derek's back while Derek reached for the lube and a condom from the bedside, still laughing.

“I want you on your hands and knees,” Derek said. “I want to pull your head back while I'm fucking you.”

Aaron stopped laughing, his breath caught by the image. “God,” he managed to get out, and rolled over without a word of protest. 

He got up on his knees and spread them. Derek's lubed fingers were immediately at his hole, rubbing it, playing with it, carefully scratching down to his perineum and balls and back again. Derek loved the prep, and Aaron bit his lip and pressed forehead into his forearms, because he loved it, too.

The leash was heavy on his back. It moved with Derek and it wasn't quite long enough that Aaron couldn't feel the pull of it. Derek slipped a finger inside and twisted it, but quickly graduated to two. Aaron was ready for it, he wanted it. He spread his knees wider and raised his ass a little higher, and he couldn't help rocking back against Derek's hand.

Derek pressed kisses to the small of his back. “Yeah, you want it, don't you?”

Aaron laughed again, breathlessly. “Yes, oh great profiler,” he said.

Derek snorted and pulled his fingers free. Aaron lost contact with him while Derek put on the condom and lubed his cock. He waited with impatience, his own cock heavy and hard and bobbing between his legs. Ordinarily he'd reach down and start stroking, but the collar made him hesitate.

“Look at you waiting for me.” Derek sounded pleased, and Aaron flushed at the implied praise. “Come on,” Derek added, tugging at the leash. “Up,” he said, command in his voice, and Aaron lifted himself and planted his hands firmly on the bed.

Derek leaned over him. “Good boy,” he murmured into Aaron's ear.

Aaron groaned and turned his head, seeking a kiss, but Derek had already pulled away. He felt Derek's cock at his opening and then Derek was inside him, moving steadily until his hips rested against Aaron's ass. Aaron struggled for breath, struggled to stay in position. Hands and knees was never as easy as it sounded.

Derek gave the leash a little tug. “Okay?”

“Yes,” Aaron said, squeezing his ass around Derek's cock. He startled when Derek gently slapped his ass.

“Don't do that,” Derek said. He stroked a hand down Aaron's spine. “I want you to take what I give you. Is that okay?”

“ _Derek_ ,” Aaron said. He was surprised by the whine in his voice.

Derek chuckled and rolled his hips. “Keep your head up,” he said, and he sounded altogether too pleased with himself for Aaron's liking.

There wasn't much Aaron could do about it. Derek tightened the leash and Aaron lifted his head up to accommodate it. He felt owned, collared and positioned to Derek's liking. It should have been humiliating, but it wasn't. Derek fucked him steadily, smoothed his free hand across Aaron's skin, whispered words of praise and endearment. With Derek, there was only trust, and the sense of being valued. The absence of violence was absolute.

Derek didn't last long. He came with a grunt and a particularly sharp tug on the leash, then curled around Aaron, wrapped his arms around Aaron's chest and twisted them down until they lay on their sides. Aaron reached back and grasped Derek's hip, urging him closer.

Derek kissed his shoulder. “Gonna take care of you,” he whispered, reaching around for Aaron's dick. Aaron smiled. Derek was half out of it, but Aaron knew he meant it in more ways than one.

-

Aaron woke up a couple of hours later. He was lying on his back against Derek, whose hand rested on his throat. He was fingering Aaron's collar, the gesture casually possessive. Aaron sighed, and Derek tightened his arms.

“You okay?”

Aaron hummed his confirmation, and went back to sleep.


End file.
